# *-*- coding:utf-8 -*-
# @Author  : Eliza
# @Time    : 2021/7/18 1:02
# @Software : RubyMine

a = 12
b = 19
if a < 1
  puts a + 1
elsif a < 5
  puts a + 5
elsif a < 7
  puts a + 7

else
  puts a
  unless a > 20 # unless 只要不
    puts b
  end
end
num = 17
case num
when 1
  puts num + 1
when 2
  puts num + 2
when 3
  puts num + 3
else
  puts "ooooooo"
end